Method of making asphalt



Patented Jan. 19, 1932 UNITED STATES PATENT orrlcs NATHANIEL E. LOOMIIS, OF WESTFIELD, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE METHOD OF MAKING ASPHALT Application filed March 28, 1928. Serial No. 265,263.

This invention relates to the manufacture of commercial asphalt from petroleum oils containing the same. It comprises broadly a method in which asphalt-containing oil is passed in a confined stream through a heating zone, vapors are separated from the heated oil, and the liquid residuum is then reduced in vacuum to the desired specification asphalt.

The drawing is an elevation with parts in section of a preferred form of apparatus in which my method may be conducted.

Tubular heater 1 may be of any suitable type. It is surrounded by fire brick setting 2 and heated by means of burner 3 or any equivalent heating device. The heater 1 receives asphalt-containing oil through supply pipe 4 and discharges the heated product through discharge pipe 5 into separator 6. Any form of separator may be used but I prefer for this purpose a drum as illustrated, the principal dimension being vertically disposed, which drum receives the heated material at or near its mid-portion. Below the point of introduction of the heated material the drum carries transverse partitions 7 which in turn are equipped-with overflow pipes 7a and vapor distributors (bell caps) 7 b. The perforate pipe 70 controlled by the valve 7d is adapted to discharge steam or other gas into the drum-at or near the base.

Vapors separate in 6 and are conducted away through pipe 8 to condenser 9, which is supplied with cooling fluid by means of pipes 9a and 9b. The condensate asses through pipe 10 to receiving tan 11. Uncondensed gases ma be vented by operating valve 12, control ing pipe 13 or alternatively the separator, condenser and 'receiving tank may be operated under partial vacuum by means of vacuum pump 14 connected to the described system through the pipes 13 and 15. The condensate collecting in 11 may be withdrawn continuously or periodically as desired through pipe 16 by means of pump 17 and discharged through pipe 18 to an accumulator.

The liquidresiduum from separator 6 is withdrawn preferably in a continuous man- 50 ner through pipe 19 by means of pump 20 and discharged through the pipe 21 and manifold 22 to a still such as 23. This still is connected to the vapor line 24 discharging into condenser 25. The condenser is supplied with cooling fluid by means of pipes 25a and 25b. Condensate from the condenser passes on through the pipe 26 into receiving tank 27. The still 23, condenser and receiving tankconnected thereto are maintained under vacuum by means of vacuum pump 28 connected to the tank 27 through pipe 29. Gases discharged from the vacuum pump pass through pipe 30 to a gas accumulator.

The condensate from tank 27 may be withdrawn continuously or periodically as desired through the pipe 31 by means of pump 32 and discharging to an accumulator through pipe 33. The still 23 is provided with the pipe 34 controlled by the valve 35 for the continuous or periodicwithdrawal of liquid therefrom. It is also provided with perforated pipe 36 controlled by valve 37 adapted to discharge gaseous material, such as steam, into the still 23 at a point below the normal liquid level therein. The still 23 is also provided with a refractory setting 38 and is adapted to be heated by means of burner 39.

While I may, if desired, operate continuously employing only the still 23 and con-.

nected equipment, I preferably employ in addition the stills 40 and 41. These have been diagramn'iatically indicated and are not more fully dcscribedforthe reason that they are duplicates of the still 23 and operated in conjunction with duplicate auxiliary equipment. When so operating, I divert liquid residuum from the separator 6 to one of the stills, 23, 40 or 41 by-manipulation of the valves 42, 43 and 44 and accumulate a'substantial quantity of residuum in the particular still. The supply is then diverted to another still and the finishing of the accumulated charge is commenced. I preferably reduce the accumulated material in the still to finished commercial asphalt by the application of vacuum thereto. The separation may be facilitated by the introduction of steam (preferably superheated) through distribu duction, conducting away tor 86. Additional heat, if necessary, is furnished by means of the burner 39.

I preferably operate the equipment herein above described on an asphalt-containing crude oil. This material may have been preliminarily topped or divested of its lighter constituents in any suitable equipment. The asphalt-containing oil is preferably heated by means of tubular heater 1 to such an extent that the vapor separating in separator 6 leaves a liquid residuum withdrawn from said separator equivalent to Within 5% (referred to the original crude as 100%) of the eventual yield of finished asphalt.

As a practical example of the operation of my process, a Colombia crude was topped to leave a 52% residuum. Thisresiduum was heated in the tubular heater to such an extent that vapors were evolved in separator 6 equivalent to 26.5% of the original crude. A pitch bottoms equivalent to 25.5% on the original crude was continuously withdrawn from the separator and then reduced in vacuum. This reduction was carried out by means of the contained heat of the oil and was assisted by passing superheated steam through the liquid. The vacuum at the end of the run corresponded to an absolute pressure of about 25 mm. of mercury.

\Vhen the bottoms had been reduced to the desired specifications, namely, a' penetration of 55 at 77 F., the operation was discontinued and the product withdrawn. The net yield of finished asphalt was equivalent to 21% of the original crude.

The foregoing is for purposes of illustration and not to be construed in limitation of the invention. The invention, moreover, is not limited to the apparatus specifically described but may be practiced in apparatus of any suitable type. It is my intention that the invention be limited only by the appended claims of their equivalents in which it is my purpose to claim all novelty inherent in the invention.

I claim:

1. The method of making asphalt from asphalt-containing petroleum oil, which comprises passing the oil in a confined stream with uninterrupted flow through a zone of heat, discharging the heated oil into a separating zone in which the oil is separated into vapors and a first liquid residuum or pitch bottoms especially adapted for asphalt prothe separated vapors from the separating. zone, continuously transferring the hot first liquid residuum in batches to azone of immediately subsequent batch treatment maintained under vacuum to partially vaporize the said first residuum and reduce the same to a second residuum of commercial asphalt.

2. Method according to claim 1, in which the first liquid residuum or pitch bottoms is formed by discharging the hot stream of oil into a separating zone, throu h which the unvaporized oil is permitted to ow downwardly over a series 0 liquid-vapor contact stages in the presence of steam.

' 3. The method of making asphalt from asphalt-containing petroleumoil, which comprises passing the oil in a confined stream with uninterrupted flow through a zone of heat, discharging the heated oil into a separating zone in which the oil is separated into vapor and a first liquid residuum or pitch bottoms especially adapted for asphalt production, conducting away the vapor so separated, continuously transferring the hot first liquid residuum in batches to a zone of immediately subsequent batch treatment maintained under vacuum and heating the said first liquid residuum in said zone maintained under vacuum to partially vaporize and reduce the same to a second residuum of commercial asphalt:

4. The method of making asphalt from asphalt-containing petroleum oil, which com prises passing the oil in a confined stream with uninterrupted flow through a zone of heat, discharging the heated oil into a separating zone maintained under vacuum in which the oil is separated into vapor and a first-liquid residuum or pitch bottoms especially adapted for asphalt production, conducting away the vapor so se arated, continuously transferring the hot rst li uid residuum to a second zone maintaine under vacuum and further heating the said first liquid residuum in said second zone to partially vaporize and reduce the same to a second residuum of commercial asphalt.

5. The method of making asphalt from asphalt-containing crude oil, which comprises passing the oil with or without a preliminary topping in a confined stream with uninterrupted flow through a zone of heat, discharging the heated crude oil into a separating zone in which the oil is separated into vapor and a first liquid residuum or pitch bottoms especially adapted for asphalt production, conducting away the vapor so separated, continuously transferring the hot first liquid residuum to a zone maintained under vacuum and further heating the first liquid residuum in said zone maintained under vacuum to partially vaporize and reduce the same to form a second residuum of commercial asphalt, the difference in amount between said first liquid residuum and said second residuum being less than 5% of the crude oil originally taken.

NATHANIEL E. LOOMIS. 

